import java.util.Scanner;

/*
   字符串编码
 */
public class StringEncoding {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str  = sc.nextLine();
        sc.close();
        char c[] = str.toCharArray();
        for (int i =0 ; i < c.length ; i++){
            int a = c[i]-'0';
            int b = c[i+1]-'0';
            int sum = a*10+b;
            if (sum < 27){
                char ch = (char) (sum+64);
                System.out.print(ch);
                i++;
            } else {
                char ch = (char) (a+64);
                System.out.print(ch);
            }
        }
    }
}
